Inspired by an image that was uploaded to Pixabay by geralt
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
8 by 8 pixels, and just what the title says.
Source pixilated
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Classic 45-degree pattern, light version.
Source Luke McDonald
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A blue gray fabric-like texture for websites. An yet another fabric-like texture. It has subtle vertical and diagonal stripes to it.
Source V. Hartikainen
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Prismatic Polyskelion Pattern No Background
Source GDJ
An alternative colour scheme to the original seamless pattern.
Source Firkin
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen